Device for the graphic representation op functions



April 28, 1925. 1,536,040

. P. L. MERGIER Er Al. v

DEvIcE FON THE GRAPHIC REPRESENTATION oF FUNCTIONS Filed Julie 4, 1res l 2 ZW ,l i T N Tlmml j/ Patented Apr. 28, 1925.

UNITED STATES vPATENT OFFICE.

PAUL LOUIS MERGIER AND HENRI EMILE GUIBERTEAU, OF PARIS, FRANCE,

` DEVICE FOR THE GRAPHIC REPRESENTATION QF FUNCTIONS.

.Application filed June 4,

To ZZ whom t may concern.'

Be it known that we, PAUL L'oUrs Mnncrnn and HENRI EMILE GUiBnnTnAU, citizens of the French Republic, both residing at Paris, France, have invented new and useful Tmprovements in a Device for the Graphic Representation of Functions, of which the following is the specification.

This invention relates to a device for the graphic representation of functions.

Up to now, the graphic representation of the functions was made by tracing on a sheet of paper or a board suitably divided for f permitting the rapid measurement of thc coordinates. This system has several inconveniences: in case the board is vertically arranged, against a wall for instance, the trac` ing is relatively difficult and, on the other hand, any error necessitates erasure which spoils the correct tracings already executed at the same place. On the other hand, as the diagrams are often used for laying out a rather large number of different curves, it was necessary to employ inks of various colors; now, it is dificult, after a certain interval of time of obtaining inks of rigorously similar colors, or the colors of which modify in the same manner by exposure tothe air.

The device forming the subject matter of the invention permits the tracing of the graphic representations of functions by means of material lines (textile threads or bands, wires or metallic bands) connecting the points ofeach curve which have been previously7 determined.

This device has therefore the following advantages:

1. It does not necessitate the use of any tracing member proper, thus avoiding the danger of spots, for instance and permits the arrangement of diagrams in any position.

2. Any error made is easily repaired by displacement of the material line, without leaving trace of the correction and without damaging the tracings already executed.

3. It is possible to do away with a curve of a diagram, by removing the material line constituting the same, without damaging the other tracings.

4.-. The same board can be used indefinitely.

The device forming the subject matter of this invention is essentially characterized in that it is constituted by several combs separated by bars, the teeth of the combs extending beyond the bars, the latter serving more- 1.923. Serial No. 643,471.

over to secure the combs on a plane support, in the manner more fully indicated hereafter. The threads or wires which serve to represent the curves are hooked between two successive teeth of the combs, so as to pass in the recess the ordinate of which corresaonds to that of the point through which be curve must pass.

In yorder that the invention may be clearly understood, a form for carrying it out has been illustrated in the accompanying drawing in which:

Fig. 1 illustrates a comb which can be used as previously indicated.

Figs. 2 and 3 illustrate modifications.

Fig. 4 is a plan view of the diagram obtained.'

Fig. 5 is a section according to line A-A Fig. 6 is a section according to line B-B.

is a section according to line C-C.

The combs 1 are mounted in the following manner on a small plane rectangular board 10 (Figs. 5 and 6). On two opposed edges of this board 10 are secured, by means of screws 11 and 11, small strips 12 and 12, cut away at 13 and 13 for forming slides (Fig. 6). The combs 1 are adjustable between the small strips 12 and 12 and at right angles tothe same, and moreover they are separated by small bars 3 sliding in the slides 13 and'13, the shape of which is for instance that of a rabbet. The end bars 4. and li" are secured to member 1.57 by means of screws 5 and 5 so that the cl mping' of the combs 1 between the small sticks is suiiicient for immobilizingl die whole structure.

The small bars 3. 1L and fl are provided with graduations 6 facilitating' the reading. The teeth of the combs can also be regularly colored in agreement with the graduations of the said bars 3.

These bars 3 which determine the spacing apart of the combs may be of the same width or of different widths.

A diagram with Cartesian. coordinates has been shown in Fig. 4 the curves being constituted by the threads or wires .7.

The small bars 3, il, 4: and 12 are preferably plated with Celluloid or other similar materials, so as to be able to trace any notes. signs or reference marks.

The wires or threads 7 which represent lthe curves, must be fitted between the teeth of the combs. They recesses 2 between the teeth can be rectilinear,.as shown in Fig. 1, or they can be Wider at the base than to- (iii yai-

, bars, ineans `for securing the bars and the .escaping from the teeth.

Wards .their iniddleportion k2) or towards theirtop Fig.. These twoilatter arrangements permit o introducing the thread or Wire at Vthe Abottom -of the recesses, owing to the resiliency of the teeth, but prevent the `accidental escape of vthe said thread or Wire.

The threads or Wires are each held at vone oic their ends by a bead 1.3, the diaineterof which .is greater than thel distance separatingV tivo teeth ofl a' comb. i it the other end, Lthe threads l or `Wires `7 are provided.

with counterireiglits 8, ensuringtheir .tensicn, and lon which are secured plugs indicating Which rnnf'ztiofn is represented by the particular thread or Wire y Wires can also be nioiintedforensuringtheir The threads por tension on a Winding device composed,l 'of a small piilley) the artis ,ot which is Vconstitutedby a screnv ltsecured in the sinall boardy lO.

uit is also possible to provide' Vprotecting devices for the diagrams obtained; kEach coinb can be; for instance, coiered bf; aacap 15, which kprevents the thread vor Wire vfrom What We claiin as ourinventiou and desire to securebjT Letters Patentis l. In a device for the graphic*representaj vtion of functions, a plane supprt, bars resting' on the support', a` p'luralitj,7 oit combs, each interposed between tivo successive bars, the teeth 'of .the coinbs projecting); above the each between tivo-successive bars` the teeth i i a vi v `of the combsv proJecting; beyond the bars,

n'ieans for securing' the bars and the. combs on thesupport, threads for passing betiveen the teeth of vthe coinbs, ineai'i's for securing the threads at one of theirends vto one of the l combs, and -ineans for 'holding Athe threads in a stretched condition.

,and'cut laway for termin 3. Ina device tor the :graphic representation of ftinct-ions, a planeviectangtilir support, Vtivo strips secured to the support, and Aparallel to ltwo 'opposed edgQS :of zthevsanie, the strips being' cut aivav to 'torni slideways, ybars resting `on .the support between the two strips and at Vright angles' thereto, and slidable in Vthe slide \vays,. coinbs, each inter-` posed betiveen tivo successive bars, the teeth oi the coinbsy extending bevond the bars, Ascrews securing the end barsfto theL support, threads .passing between the teeth of the conibs, ,means securing .-th'eseithreads at one of their-ends to one of the conibs, .and ,njieans iholding' these threads in ii-stretched'condi- .tioni 4. ln a device orthe graphic representav,tion of functions; a plane rectangular support, tivo strips secured onthe supportand parallel'to two, opposed edges of the saine 0f slidenayS, bars resting on the support between ,the tivo strips and atright angles thereto, and Slidable in the ,slidewajvs combs, each interpbsed between `tivo siiccessive'bars, :the teeth of.. the

combs 'eX-tending' beyondxthe bars, screws curing the end bars tothe support, threads passing between vthe `teeth of the combs, Va .head/secured att-he 'endfof each thread and of Ygreater diameter than the' teeth gaps, and .means for holding the ,threads fin .a stretched condition; Y

5; ln .adevice Yfor the graphic representa- .tionA of'lfunctio'ns, a plane rectangular supporntwo strips secured Vori `the support and parallel lto ltwo opposed edges thereof,` and cut away for forming slide'ways, .bars restand at right angles thereto, kandsidable 4,in the slideivays,` coinbs, each interposed Abetween tivo successivebars,l the teeth of the conibs extending` beyond the bars. screws securing' ythe-end bars t'o the support, threads passing' between the teeth *of ,tlieb'olnbs, a bead secured at the end oit each tlii'ef., Yand oi greater diaineterthaii the distance separating two teeth, and pulleys iiieunted on the ether lends of 90 ing` on. the support between the.V tivol strips 

